Reader Steven Alford asks:
When I click on a single photo on, say, my iPad, a small clock face rotates in the lower righthand corner and the photo is displayed. Is that photo downloaded to my device and does it take up room on the device? Or, are only photos taken by the device stored on the device?
If you’re using iCloud Photo Library, you can set synchronization such that Photos in iOS and OS X only caches thumbnail previews of images. (In iOS: Settings > Photos & Camera and set Optimize iPhone/iPad Storage. In Photos for OS X: Preferences > iCloud, and set Optimize Mac Storage.)
Each OS decides when to dump full-resolution versions of photos, even those imported, uploaded, or taken by the device on which Photos is running, after those images are uploaded to iCloud. This can happen immediately if storage space is low.
When you see the circle filling as an image loads, that media is at least temporarily stored at full-resolution on the device. Navigate away and there’s no guarantee that it won’t be purged from memory in moments.
Ask Mac 911
We’re always looking for problems to solve! Email yours to mac911@macworld.com including screen captures as appropriate. Mac 911 cannot reply to email with troubleshooting advice nor can we publish answers to every question.
Author: Glenn Fleishman, Senior Contributor
Glenn Fleishman’s most recent books include Take Control of iOS and iPadOS Privacy and Security, Take Control of Calendar and Reminders, and Take Control of Securing Your Mac. In his spare time, he writes about printing and type history. He’s a senior contributor to Macworld, where he writes Mac 911.